Training:

• 2007 Microsoft Office - Learning Portal
  • Course 3370: Getting Started with Microsoft Office SharePoint Server 2007 (Beta)
  • Course 3369: Getting Started with Windows SharePoint Services 3.0 (Beta)
  • Course 3199: Getting Started with the 2007 Microsoft Office System (Beta)
  • Course 4698: What's New in Microsoft Office Groove 2007

• 2007 Microsoft Office System SDKs & Tech Articles
• Office SharePoint Server 2007 (Beta) SDK
• Windows SharePoint Services V3 (Beta) SDK
• 2007 Office System Starter Kit: Enterprise Content Management Starter Kit
• MOSS 2007 Migration Center
• Windows SharePoint Services Beta 2 IT Pro Documentation
• Book (FREE):  7 Development Projects for Microsoft Office SharePoint Server 2007 and Windows SharePoint Services 3.0 (via Erika Ehrli)

• Channel 9 – Videos, Screencasts, Podcastshttp://channel9.msdn.com/tags/MS+Office (Via Chris Johnson)
• In the Office - New Capabilities of Office 2007 for Developers
• MSDN TV: Building Custom Solutions with Excel Services
• Office Developer Center
• 2007 Office System: How Do I ScreenCasts
  • Creating and Deploying a Feature for Windows SharePoint Services V3
    Step through the process of using Visual Studio to create a custom feature and an associated assembly DLL.   
  • Creating and Using Event Handlers in Windows SharePoint Services V3
    Create a list item receiver class to handle both synchronous events as well as asynchronous events. 
  • Creating Custom Document Information Panels
    Discover the integration that exists between Document Information Panels and content types in Windows SharePoint Services V3.
  • Creating Custom Workflows with the SharePoint Designer 2007
    Build a custom workflow using the wizard provided by SharePoint Designer 2007.
  • Customizing a Windows SharePoint Services V3 site with the SharePoint Designer 2007
    Understand the difference between page templates and page instances and then learn how to customize your pages.  
  • Extending the Office 2007 UI with a Custom Ribbon
    Create a shared add-in with Visual Studio 2005 that extends the new user interface with a custom ribbon.  
  • Extending the Office 2007 UI with a Custom Task Pane
    Create a shared add-in with Visual Studio 2005 that extends the new user interface with a custom task pane.
  • Getting Up and Running with Excel Services
    Step through the process of configuring Excel Services so that you can publish an Excel spreadsheet to a Windows SharePoint Services V3 site.  
  • Generating Office Documents using the New XML Open File Formats
    Generate, read and modify documents without going through the object model of the hosting Office application.    

Web Parts:

• SharePoint 2007 Web Part Series by Sahil via Andrew
  • ASP.NET 2.0 WebPart Communication: The Preface to Sharepoint 2007 WebPart communication
  • Writing Custom Webparts for Sharepoint 2007
  • Sharepoint 2007 WebParts Communication
  • Writing custom editors for Sharepoint 2007 and ASP.NET 2.0 WebParts
  • Sharepoint 2007 WebPart Connections - The Theory before the Code

Additional Resources:

• JOPX 2007 Microsoft Office SharePoint Server Links